Many mechanical operations require that one or more workpieces be held stationary for a period of time. Various types of clamps and other devices are known in the art for securing a workpiece in a desired position to facilitate an operation on the workpiece.
One apparatus for securing one or more workpieces is disclosed in my U.S. Pat. No. 5,624,106. The gripping device disclosed in this patent has a gripper wall which is tapered from the upper portion to the lower portion where the tapered gripper wall provides the holding force. The gripping member includes a through bore having a conical surface where one side is more recessed than the other and the fastener bears against the shallow conical surface thereby creating the downward inward holding force. The gripping device also includes a tapered head and further includes a countersink having first and second conical surfaces the first conical surface being in axial alignment with, the through bore and the second conical surface having an axis offset from that of the through bore whereby the tapered head of the fastener bears against the countersink when the fastener is secured to the fixture thereby creating the downward inward holding force.
In view of the foregoing, it can be understood that each gripping device of my U.S. Pat. No. 5,624,106 requires substantial machining to manufacture and therefore manufacturing gripping devices of different sizes to hold different sizes of workpieces requires machining of each size gripping device. Furthermore, a principle objective is to create an optimum central holding force on round or out of round or odd material objects for machining or even welding pieces together.